Missing text motification

[AC Question]

Usually on my status bar I can see the text icon. Also on my lock screen, i can usually see who a text is from. I can no longer see this. I have checked everywhere. The notifications are on, the "show content on lock screen" is on. I'm not sure how to fix this.
Please help.

 

[B. Diddy]

Welcome to Android Central! Which phone? Any power-saving modes or apps on? Is Restrict Background Data turned on in Settings>Data Usage​?